Typically I machine stitch with the right sides of collar and neckline together, and then flip it but I would like to learn the method shown in the video.
My patterns have 3/8" SA all around including the shoulder, neck line, and arm hole seams. I can trim 3/8" in the edges of the under collar and attach it that way but there isn't much of the neckline to sew to.
Would it be correct if I extended the neckline SA of the front and back patterns another 3/8" to give the collar more body to sew on?
Thanks
Yes that is correct, I have not drafted the pattern using the video but these are patterns I already had and wish to use. My patterns do not have any inlay in them so I think it will be necessary to add some extra to the neckline of the front/back patterns.. but I am not sure where and how much to add.